Vehicle headlight



July 24, 1928.

W. H. WOOD I VEHICLE HEADLIGHT Filed Jan. 1926 illiam H mm; f

Patented uly 24, 1928.

UNITED STATES WILLIAM H. WOOD, OF SOUTH EUCLID, OHIO.

VEHICLE HEADLIGHT.

Application filed January 16. 1926. Serial No. 81,730.

This invention relates to vehicle headlights and has for its object the provision of a. new and improved bulb and wiring whereby improved lighting is obtained and whereby functions now requiring plural bulbs may be performed with one bulb; the provision of a plural filament bulb which may be installed either side up: the provision of a bulb having added safeguards against completely burning out; the provision of a single bulb containing two driving lights and a parking light; the provision of new and simplified means for securing automobile illumination: while further objects and advantages will become apparcut as the description proceeds.

In the drawings I have shown one of the many physical forms in which my inventive idea. can be embodied. Fig. 1 is a sectional view through a lamp reflector and bulb containing my invention, the wiring being shown diagrammatical: Fig. 2 is a front elevation of the lamp bulb shown in Fig. 1: Fig. 3 is a perspective view of the filaments much enlarged to show their preferred relative position: Fig. 4 illustrates a modified form of lamp bulb together with a portion of the reflector. on which it is used.

The reflector 1 may be of any kind which has a focal point, and has a socket 2 receiving the base 3 of an incandescent bulb. These bases are generally cylindrical with two opposed bayonet studs 4 received in slots in the socket so they can be applied either side up. The socket is grounded to the negative pole of a storage battery 5.

According to my invention I provide the bulb with three independently usable fila ments 6, 7. 8. Preferably these are made of concentrated shape each consisting of a small helix of fine wire, all three filaments being joined at one end to a single support-,

ing wire9. which is grounded to the base as shown in Fig. 3 and the other ends of the filaments being joined to separate wires 10. 11, 12, respectively connected to contacts 13. 14, 15 on the base, insulated from the base and from each other. With the base is used a connecting member having three companion contacts connected by circuits 16, 17. 18 to the three contact points 19. 20, 21 of a switch 22. The circuit 18 which leads to the lowermost filament 8 includes a resistance element 23.

same candle power, and it is'also preferable, but not essential to make them of V-shape with their'apices turned away from the base. Furthermore I prefer to incline the Vs together so that their apices come close together at the center of the bulb which is so lo'i'ated as to coincide substantially with the focal point of the reflector. This causes the middle filament to assume the horizontal position customary for many years; the upper filament is located in and confined to an oblique plane as set forth in my Patent No. 1,533,360,. issued April 14:, 1925, and thereby casts a downwardly deflected beam advantageous for city driving or passing other vehicles. The lowermost filament casts its rays upwardly but these are not objectionable because of the resistance 23.

lVhen filament 7 is used an intense distance beam is produced. When filament 6 is used the lightbeam is depressed at the outer sides, glaring rays are cut ofi' and passing light is provided. When the filament 8 is used a dim light is produced for parking by reason of the resistance. No care is required in installin the lamp since it operates the same either side up. The filament 6 is generally the most used and hence the first to burn out, whereupon by turning the bulb to bring the filament 8 uppermost a new driving light produced, since this never burns out while parking.

It will be apparent to those skilled in the art that many advantages are secured by this arrangement-of filaments, and by the use of three filaments, two arranged to give an equal cand'lepower and the third a lower candlepower regardless whether 'my preferred converging arrangement be employed. In Fig. 4 I have shown the two equal powered filaments 25, 26 as located parallel to each other, one above and one below the axis of the base 3 and the third 27 located entirely at the rear thereof and well away from the .focal center. In this case, however, the bulb loses. the reversible feature.

What I claim is:

1. In a vehicle headlight, a substantially paraboloid reflector, a lamp bulb comprising three independent concentrated filaments one above the other, one of which defines and is substantially confined within the horizontal plane which includes the reflector axis, and the other two of which define and are substantially confined within planes which intersect said first plane obliquely along a line perpendicular to said reflector axis substantially at its focal point, said last two filaments being located in regions between the vertex and parameter of said reflector, in combination with three circuits,

7 one for each filament, and a switch and bat- ,tery, that circuit which corresponds to the lowermost filament including a resistance element.

2. In a vehicle headlight, a reflector, having an axis and a focal point and a lamp bulb having three independent V-shaped filaments located with their apices' close to the focal point and to each other, the planes of said Vs intersecting each other in a horizontal. line perpendicular to said reflector axis substantially at said focal point and thence diverging toward the lamp base.

signature.

WILLIAM H. woon. 

